Cracking the Code

IEEE: Institute for Electrical and Electronics Engineers TryEngineering
Type Category
Instructional Materials
Activity , Code , Informative Text , Lesson/Lesson Plan , Problem Set
This resource, vetted by NSTA curators, is provided to teachers along with suggested modifications to make it more in line with the vision of the NGSS. While not considered to be "fully aligned," the resources and expert recommendations provide teachers with concrete examples and expert guidance using the EQuIP rubric to adapted existing resources. Read more here.



This resource enables students to understand a technology that is such an integral part of our daily lives, yet little understood.  It extends the information transfer lessons already on the NGSS Hub to computerized barcoding. Students will learn about encoding and decoding, then work in teams to design an improved information encoding system. Understanding the impact of engineering and technology on society is an integral outcome of these lessons. Strong cross-curricular connections are also present with the integration of informational text to support their understanding and grade appropriate application of standards for mathematics.

Intended Audience

Educator and learner
Educational Level
  • Grade 4
  • Upper Elementary
  • Middle School
  • High School
Access Restrictions

Free access - The right to view and/or download material without financial, registration, or excessive advertising barriers.

Performance Expectations

4-PS4-3 Generate and compare multiple solutions that use patterns to transfer information.

Clarification Statement: Examples of solutions could include drums sending coded information through sound waves, using a grid of 1’s and 0’s representing black and white to send information about a picture, and using Morse code to send text.

Assessment Boundary: none

This resource is explicitly designed to build towards this performance expectation.

Comments about Including the Performance Expectation
Students will apply their learning by identifying three shortcomings of the current barcode system. They will develop a plan for a prototype that will solve the problems they have identified, while also adding new benefits to the system. Students will then present their ideas to the class, which will include a description of how their system prototype works, an illustration of the product or situation where it will be used, and an advertisement promoting its features. The sharing of student’s ideas will enable them to compare solutions.

Science and Engineering Practices

This resource appears to be designed to build towards this science and engineering practice, though the resource developer has not explicitly stated so.

Comments about Including the Science and Engineering Practice
Comparing the differences between systems already in existence such as UPC, and SKU barcodes, QR codes, and even postal barcodes is suggested. This will broaden student’s understanding and enhance their ability to generate solutions to the problems identified with barcoding systems. This will also enable them to better establish the criteria and constraints for the design challenge.

Disciplinary Core Ideas

This resource was not designed to build towards this disciplinary core idea, but can be used to build towards it using the suggestions provided below.

Comments about Including the Disciplinary Core Idea
Many solutions to the shortcomings of the current barcode system would not be testable in the classroom. To better align the resource to this Disciplinary Core Idea, it is recommended that the scope of the challenge be constrained to the patterns of information transfer. Can students come up coding system that requires less than 12 digits? Or that does not require as many mathematical steps to check the codes? Once the challenge is defined, students can work as a class to establish criteria and constraints.

This resource appears to be designed to build towards this disciplinary core idea, though the resource developer has not explicitly stated so.

Comments about Including the Disciplinary Core Idea
Barcode and QR code apps on a mobile phone can easily demonstrate how cell phone can receive and transmit digitized information over a distance without degradation. For classes that have access to tablet devices, a QR code scavenger hunt is a great way to experience this transmission firsthand. For computers, a barcode reader is needed that reads the bars, checks the number, and transmits the information to the computer in text format. The computer is then able to identify the item immediately using a product database.

Crosscutting Concepts

This resource appears to be designed to build towards this crosscutting concept, though the resource developer has not explicitly stated so.

Comments about Including the Crosscutting Concept
All UPC (Universal Product Codes) barcodes have 12 digits. All have a last digit that checks if the codes are correct. The first six numbers sort products by vendor. The next five digits identify the specific product. Identifying patterns in these similarities and differences can be easily accomplished by having them compare the UPC barcodes of a family of items (for example, Hunt’s brand tomato sauce, tomato paste, whole, crushed, stewed and diced tomatoes). Students could then compare more than one family of items, and be challenged by presenting them with mystery products where they are asked to identify the vendor using the pattern from the families they have explored.

Resource Quality

  • Alignment to the Dimensions of the NGSS: ‘Cracking the Code” engages students in the real world technology of barcoding to make sense how digitized information can be transmitted over long distances. It includes an engineering component that enables them to propose optimized solutions to the current systems. It clearly demonstrates the interdependence of science, engineering and technology. It also engages students in the reading of informational text and mathematical calculations, providing grade-appropriate connections to the Common Core Standards for English/Language Arts (4.RI.3, 4.RI.7) and Mathematics (4.OA.B.4). To strengthen the alignment of this resource to the dimensions, it is first recommended that the students engage in the UPC Database before reading the informational text. Patterns of information are assumed and need to be made explicit as the barcodes are investigated and discussed. Finally, it is suggested that the scope of the engineering be constrained to challenges that can be tested in the classroom.

  • Instructional Supports: This resource engages students in an authentic phenomenon that reflects the practice of science and engineering as experienced in the real world. It provides first-hand experiences as to how product information is encoded and decoded. It also enables students to apply their understanding to optimizing the barcode system, and represent, express and justify their ideas through an engineering challenge. Strategies for differentiation of instruction are not provided for. Chunking is recommended to break the reading and mathematical problem solving into manageable pieces.

  • Monitoring Student Progress: There are multiple opportunities for students to demonstrate their understanding as they engage in the UPC Database, as they read and discuss the informational text, as they solve the mathematical problem set that demonstrates how barcodes work, and as they apply their learning to the design challenge. Student’s responses to the questions on page 9 could also yield assessment information.

  • Quality of Technological Interactivity: This lesson enables students to engage in a technological system. The use of devices such as tablets to enable the reading of barcodes is recommended to enhance the technological interactivity of this resource. It is also suggested that barcode digits of popular brands as opposed to store brands be used to search for products.